1
|
Scrima S, Lambrughi M, Tiberti M, Fadda E, Papaleo E. ASM variants in the spotlight: A structure-based atlas for unraveling pathogenic mechanisms in lysosomal acid sphingomyelinase. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167260. [PMID: 38782304 DOI: 10.1016/j.bbadis.2024.167260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/30/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024]
Abstract
Lysosomal acid sphingomyelinase (ASM), a critical enzyme in lipid metabolism encoded by the SMPD1 gene, plays a crucial role in sphingomyelin hydrolysis in lysosomes. ASM deficiency leads to acid sphingomyelinase deficiency, a rare genetic disorder with diverse clinical manifestations, and the protein can be found mutated in other diseases. We employed a structure-based framework to comprehensively understand the functional implications of ASM variants, integrating pathogenicity predictions with molecular insights derived from a molecular dynamics simulation in a lysosomal membrane environment. Our analysis, encompassing over 400 variants, establishes a structural atlas of missense variants of lysosomal ASM, associating mechanistic indicators with pathogenic potential. Our study highlights variants that influence structural stability or exert local and long-range effects at functional sites. To validate our predictions, we compared them to available experimental data on residual catalytic activity in 135 ASM variants. Notably, our findings also suggest applications of the resulting data for identifying cases suited for enzyme replacement therapy. This comprehensive approach enhances the understanding of ASM variants and provides valuable insights for potential therapeutic interventions.
Collapse
Affiliation(s)
- Simone Scrima
- Cancer Structural Biology, Center for Autophagy, Recycling and Disease, Danish Cancer Institute, 2100 Copenhagen, Denmark; Cancer Systems Biology, Section for Bioinformatics, Department of Health and Technology, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Matteo Lambrughi
- Cancer Structural Biology, Center for Autophagy, Recycling and Disease, Danish Cancer Institute, 2100 Copenhagen, Denmark
| | - Matteo Tiberti
- Cancer Structural Biology, Center for Autophagy, Recycling and Disease, Danish Cancer Institute, 2100 Copenhagen, Denmark
| | - Elisa Fadda
- Department of Chemistry and Hamilton Institute, Maynooth University, Maynooth, co. Kildare, Ireland
| | - Elena Papaleo
- Cancer Structural Biology, Center for Autophagy, Recycling and Disease, Danish Cancer Institute, 2100 Copenhagen, Denmark; Cancer Systems Biology, Section for Bioinformatics, Department of Health and Technology, Technical University of Denmark, 2800 Lyngby, Denmark.
| |
Collapse
|
2
|
Romero-Moreno R, Czowski BJ, Harris L, Kuehn JF, White KA. Intracellular pH differentially regulates transcription of metabolic and signaling pathways in normal epithelial cells. J Biol Chem 2024; 300:107658. [PMID: 39128712 PMCID: PMC11489351 DOI: 10.1016/j.jbc.2024.107658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Accepted: 07/31/2024] [Indexed: 08/13/2024] Open
Abstract
Intracellular pH (pHi) dynamics regulate normal cell function, and dysregulated pHi dynamics is an emerging hallmark of cancer (constitutively increased pHi) and neurodegeneration (constitutively decreased pHi). However, the molecular mechanisms by which pHi dynamics regulate cell biology are poorly understood. Here, we discovered that altering pHi in normal human breast epithelial cells triggers global transcriptional changes. We identified 176 genes differentially regulated by pHi, with pHi-dependent genes clustering in signaling and glycolytic pathways. Using various normal epithelial cell models, we showed pH-dependent Notch homolog 1 protein expression, with increased protein abundance at high pHi. This resulted in pH-dependent downstream signaling, with increased Notch homolog 1 signaling at high pHi. We also found that high pHi increased the expression of glycolytic enzymes and regulators of pyruvate fate, including lactate dehydrogenase and pyruvate dehydrogenase kinase. These transcriptional changes were sufficient to alter lactate production, with high pHi shifting these normal epithelial cells toward a glycolytic metabolism and increasing lactate production. Thus, pHi dynamics transcriptionally regulate signaling and metabolic pathways in normal epithelial cells. Our data reveal new molecular regulators of pHi-dependent biology and a role for increased pHi in driving the acquisition of cancer-associated signaling and metabolic changes in normal human epithelial cells.
Collapse
Affiliation(s)
- Ricardo Romero-Moreno
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Brandon J Czowski
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Lindsey Harris
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jessamine F Kuehn
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Katharine A White
- Harper Cancer Research Institute, South Bend, Indiana, USA; Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.
| |
Collapse
|
3
|
Xu W, Zhao Z, Su M, Jain A, Lloyd HC, Feng EY, Cox N, Woo CM. Genesis and regulation of C-terminal cyclic imides from protein damage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.09.606997. [PMID: 39211211 PMCID: PMC11360958 DOI: 10.1101/2024.08.09.606997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
C-Terminal cyclic imides are post-translational modifications (PTMs) that can arise from spontaneous intramolecular cleavage of asparagine or glutamine residues resulting in a form of irreversible protein damage. These protein damage events are recognized and removed by the E3 ligase substrate adapter cereblon (CRBN), indicating that these aging-related modifications may require cellular quality control mechanisms to prevent deleterious effects. However, the factors that determine protein or peptide susceptibility to C-terminal cyclic imide formation or their effect on protein stability have not been explored in detail. Here, we characterize the primary and secondary structures of peptides and proteins that promote intrinsic formation of C-terminal cyclic imides in comparison to deamidation, a related form of protein damage. Extrinsic effects from solution properties and stressors on the cellular proteome additionally promote C-terminal cyclic imide formation on proteins like glutathione synthetase (GSS) that are susceptible to aggregation if the protein damage products are not removed by CRBN. This systematic investigation provides insight to the regions of the proteome that are prone to these unexpectedly frequent modifications, the effects of this form of protein damage on protein stability, and the biological role of CRBN.
Collapse
|
4
|
Kisor KP, Ruiz DG, Jacobson MP, Barber DL. A role for pH dynamics regulating transcription factor DNA binding selectivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.21.595212. [PMID: 38826444 PMCID: PMC11142074 DOI: 10.1101/2024.05.21.595212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
Collapse
|
5
|
Esteve F, Rieu T, Lehn JM. Constitutional adaptation to p Ka modulation by remote ester hydrolysis. Chem Sci 2024; 15:7092-7103. [PMID: 38756812 PMCID: PMC11095373 DOI: 10.1039/d4sc01288g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/09/2024] [Indexed: 05/18/2024] Open
Abstract
The mechanisms through which environmental conditions affect the expression of interconnected species is a key step to comprehending the principles underlying complex chemical processes. In Nature, chemical modifications triggered by the environment have a major impact on the structure and function of biomolecules and regulate different reaction pathways. Yet, minimalistic artificial systems implementing related adaptation behaviours remain barely explored. The hydrolysis of amino acid methyl esters to their corresponding amino acids leads to a drastic change in pKa (ca. 7 and 9, respectively) that protonates the free amino group at physiological conditions. Dynamic covalent libraries (DCvLs) based on amino acid methyl esters and aldehydes respond to such hydrolysis and lead to constitutional adaptation. Each of the libraries studied experiences a DCvL conversion allowing for constituent selection due to the silencing of the zwitterionic amino acids towards imine formation. The selective action of different enzymes on the DCvLs results in states with simplified constitutional distributions and transient chirality. When additional components (i.e., scavengers) that are not affected by hydrolysis are introduced into the dynamic libraries, the amino acid methyl ester hydrolysis induces the up-regulation of the constituents made of these scavenging components. In these systems, the constituent distribution is resolved from a scrambled mixture of imines to a state characterized by the predominance of a single aldimine. Remarkably, although the final libraries display higher "simplexity", the different transient states present an increased complexity that allows for the emergence of organized structures [micelle formation] and distributions [up-regulation of two antagonistic constituents]. This reactive site inhibition by a remote chemical modification resembles the scenario found in some enzymes for the regulation of their activity through proximal post-translational modifications.
Collapse
Affiliation(s)
- Ferran Esteve
- Laboratoire de Chimie Supramoléculaire, Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| | - Tanguy Rieu
- Laboratoire de Chimie Supramoléculaire, Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| | - Jean-Marie Lehn
- Laboratoire de Chimie Supramoléculaire, Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| |
Collapse
|
6
|
Wu Z, Pope SD, Ahmed NS, Leung DL, Hajjar S, Yue Q, Anand DM, Kopp EB, Okin D, Ma W, Kagan JC, Hargreaves DC, Medzhitov R, Zhou X. Control of Inflammatory Response by Tissue Microenvironment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.10.592432. [PMID: 38798655 PMCID: PMC11118380 DOI: 10.1101/2024.05.10.592432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Inflammation is an essential defense response but operates at the cost of normal functions. Whether and how the negative impact of inflammation is monitored remains largely unknown. Acidification of the tissue microenvironment is associated with inflammation. Here we investigated whether macrophages sense tissue acidification to adjust inflammatory responses. We found that acidic pH restructured the inflammatory response of macrophages in a gene-specific manner. We identified mammalian BRD4 as a novel intracellular pH sensor. Acidic pH disrupts the transcription condensates containing BRD4 and MED1, via histidine-enriched intrinsically disordered regions. Crucially, decrease in macrophage intracellular pH is necessary and sufficient to regulate transcriptional condensates in vitro and in vivo, acting as negative feedback to regulate the inflammatory response. Collectively, these findings uncovered a pH-dependent switch in transcriptional condensates that enables environmental sensing to directly control inflammation, with a broader implication for calibrating the magnitude and quality of inflammation by the inflammatory cost.
Collapse
Affiliation(s)
- Zhongyang Wu
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Scott D. Pope
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Nasiha S. Ahmed
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Diana L. Leung
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Stephanie Hajjar
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Qiuyu Yue
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing 100871, China
| | - Diya M. Anand
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| | - Elizabeth B. Kopp
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Daniel Okin
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, Massachusetts, 02115
| | - Weiyi Ma
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jonathan C. Kagan
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Diana C. Hargreaves
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Ruslan Medzhitov
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Tananbaum Center for Theoretical and Analytical Human Biology, Yale University School of Medicine
| | - Xu Zhou
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
7
|
Prakash A, Li Z, Chirasani VR, Rasquinha JA, Valentin NH, Hubbard GB, Yin G, Dohlman HG, Campbell SL. Molecular and Functional Profiling of Gαi as an Intracellular pH Sensor. RESEARCH SQUARE 2024:rs.3.rs-4203924. [PMID: 38746411 PMCID: PMC11092800 DOI: 10.21203/rs.3.rs-4203924/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Heterotrimeric G proteins (Gα, Gβ and Gγ) act downstream of G-protein-coupled receptors (GPCRs) to mediate signaling pathways that regulate various physiological processes and human disease conditions. Previously, human Gαi and its yeast homolog Gpa1 have been reported to function as intracellular pH sensors, yet the pH sensing capabilities of Gαi and the underlying mechanism remain to be established. Herein, we identify a pH sensing network within Gαi, and evaluate the consequences of pH modulation on the structure and stability of the G-protein. We find that changes over the physiological pH range significantly alter the structure and stability of Gαi-GDP, with the protein undergoing a disorder-to-order transition as the pH is raised from 6.8 to 7.5. Further, we find that modulation of intracellular pH in HEK293 cells regulates Gαi-Gβγ release. Identification of key residues in the pH-sensing network allowed the generation of low pH mimetics that attenuate Gαi-Gβγ release. Our findings, taken together, indicate that pH-dependent structural changes in Gαi alter the agonist-mediated Gβγ dissociation necessary for proper signaling.
Collapse
Affiliation(s)
- Ajit Prakash
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Zijian Li
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Venkata R. Chirasani
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Juhi A. Rasquinha
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Natalie H. Valentin
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Garrett B. Hubbard
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Guowei Yin
- The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518107, China
| | - Henrik G. Dohlman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Sharon L. Campbell
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
8
|
Zimmerman SG, Berg CA. CO2 exposure drives a rapid pH response in live adult Drosophila. PLoS One 2024; 19:e0302240. [PMID: 38625910 PMCID: PMC11020609 DOI: 10.1371/journal.pone.0302240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/29/2024] [Indexed: 04/18/2024] Open
Abstract
CO2 anesthesia is the most common method for immobilizing Drosophila for research purposes. But CO2 exposure has consequences-it can impact fertility, behavior, morphogenesis, and cytoskeletal dynamics. In this respect, Drosophila is an outstanding model for studying the impact of CO2 exposure on tissues. In this study we explored the response of intracellular pH (pHi) to a one-minute CO2 pulse using a genetically encoded, ubiquitously expressed pH sensor, tpHusion, to monitor pHi within a live, intact, whole fly. We compared wild-type flies to flies lacking Imaginal disc growth factors (Idgfs), which are chitinase-like proteins that facilitate developmental processes and the innate immune response. Morphogenetic and cytoskeletal defects in Idgf-null flies are enhanced after CO2 exposure. We found that pHi drops sharply within seconds of the beginning of a CO2 pulse and recovers over several minutes. The initial profile was nearly identical in control and Idgf-null flies but diverged as the pHi returned to normal. This study demonstrates the feasibility of monitoring pH in live adult Drosophila. Studies exploring pH homeostasis are important for understanding human pathologies associated with pH dysregulation.
Collapse
Affiliation(s)
- Sandra G. Zimmerman
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Celeste A. Berg
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|
9
|
Stock C. pH-regulated single cell migration. Pflugers Arch 2024; 476:639-658. [PMID: 38214759 PMCID: PMC11006768 DOI: 10.1007/s00424-024-02907-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/13/2024]
Abstract
Over the last two decades, extra- and intracellular pH have emerged as fundamental regulators of cell motility. Fundamental physiological and pathological processes relying on appropriate cell migration, such as embryonic development, wound healing, and a proper immune defense on the one hand, and autoimmune diseases, metastatic cancer, and the progression of certain parasitic diseases on the other, depend on surrounding pH. In addition, migrating single cells create their own localized pH nanodomains at their surface and in the cytosol. By this means, the migrating cells locally modulate their adhesion to, and the re-arrangement and digestion of, the extracellular matrix. At the same time, the cytosolic nanodomains tune cytoskeletal dynamics along the direction of movement resulting in concerted lamellipodia protrusion and rear end retraction. Extracellular pH gradients as found in wounds, inflamed tissues, or the periphery of tumors stimulate directed cell migration, and long-term exposure to acidic conditions can engender a more migratory and invasive phenotype persisting for hours up to several generations of cells after they have left the acidic milieu. In the present review, the different variants of pH-dependent single cell migration are described. The underlying pH-dependent molecular mechanisms such as conformational changes of adhesion molecules, matrix protease activity, actin (de-)polymerization, and signaling events are explained, and molecular pH sensors stimulated by H+ signaling are presented.
Collapse
Affiliation(s)
- Christian Stock
- Department of Gastroenterology, Hepatology, Infectiology & Endocrinology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| |
Collapse
|
10
|
Michl J, White B, Monterisi S, Bodmer WF, Swietach P. Phenotypic screen of sixty-eight colorectal cancer cell lines identifies CEACAM6 and CEACAM5 as markers of acid resistance. Proc Natl Acad Sci U S A 2024; 121:e2319055121. [PMID: 38502695 PMCID: PMC10990159 DOI: 10.1073/pnas.2319055121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/13/2024] [Indexed: 03/21/2024] Open
Abstract
Elevated cancer metabolism releases lactic acid and CO2 into the under-perfused tumor microenvironment, resulting in extracellular acidosis. The surviving cancer cells must adapt to this selection pressure; thus, targeting tumor acidosis is a rational therapeutic strategy to manage tumor growth. However, none of the major approved treatments are based explicitly on disrupting acid handling, signaling, or adaptations, possibly because the distinction between acid-sensitive and acid-resistant phenotypes is not clear. Here, we report pH-related phenotypes of sixty-eight colorectal cancer (CRC) cell lines by measuring i) extracellular acidification as a readout of acid production by fermentative metabolism and ii) growth of cell biomass over a range of extracellular pH (pHe) levels as a measure of the acid sensitivity of proliferation. Based on these measurements, CRC cell lines were grouped along two dimensions as "acid-sensitive"/"acid-resistant" versus "low metabolic acid production"/"high metabolic acid production." Strikingly, acid resistance was associated with the expression of CEACAM6 and CEACAM5 genes coding for two related cell-adhesion molecules, and among pH-regulating genes, of CA12. CEACAM5/6 protein levels were strongly induced by acidity, with a further induction under hypoxia in a subset of CRC lines. Lack of CEACAM6 (but not of CEACAM5) reduced cell growth and their ability to differentiate. Finally, CEACAM6 levels were strongly increased in human colorectal cancers from stage II and III patients, compared to matched samples from adjacent normal tissues. Thus, CEACAM6 is a marker of acid-resistant clones in colorectal cancer and a potential motif for targeting therapies to acidic regions within the tumors.
Collapse
Affiliation(s)
- Johanna Michl
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| | - Bobby White
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| | - Stefania Monterisi
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| | - Walter F. Bodmer
- Department of Oncology, University of Oxford, OxfordOX3 7DQ, United Kingdom
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics, University of Oxford, OxfordOX1 3PT, United Kingdom
| |
Collapse
|
11
|
Morelli M, Cabezuelo Rodríguez M, Queiroz K. A high-throughput gut-on-chip platform to study the epithelial responses to enterotoxins. Sci Rep 2024; 14:5797. [PMID: 38461178 PMCID: PMC10925042 DOI: 10.1038/s41598-024-56520-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/07/2024] [Indexed: 03/11/2024] Open
Abstract
Enterotoxins are a type of toxins that primarily affect the intestines. Understanding their harmful effects is essential for food safety and medical research. Current methods lack high-throughput, robust, and translatable models capable of characterizing toxin-specific epithelial damage. Pressing concerns regarding enterotoxin contamination of foods and emerging interest in clinical applications of enterotoxins emphasize the need for new platforms. Here, we demonstrate how Caco-2 tubules can be used to study the effect of enterotoxins on the human intestinal epithelium, reflecting toxins' distinct pathogenic mechanisms. After exposure of the model to toxins nigericin, ochratoxin A, patulin and melittin, we observed dose-dependent reductions in barrier permeability as measured by TEER, which were detected with higher sensitivity than previous studies using conventional models. Combination of LDH release assays and DRAQ7 staining allowed comprehensive evaluation of toxin cytotoxicity, which was only observed after exposure to melittin and ochratoxin A. Furthermore, the study of actin cytoskeleton allowed to assess toxin-induced changes in cell morphology, which were only caused by nigericin. Altogether, our study highlights the potential of our Caco-2 tubular model in becoming a multi-parametric and high-throughput tool to bridge the gap between current enterotoxin research and translatable in vivo models of the human intestinal epithelium.
Collapse
|
12
|
Yan R, Zhang P, Shen S, Zeng Y, Wang T, Chen Z, Ma W, Feng J, Suo C, Zhang T, Wei H, Jiang Z, Chen R, Li ST, Zhong X, Jia W, Sun L, Cang C, Zhang H, Gao P. Carnosine regulation of intracellular pH homeostasis promotes lysosome-dependent tumor immunoevasion. Nat Immunol 2024; 25:483-495. [PMID: 38177283 DOI: 10.1038/s41590-023-01719-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/28/2023] [Indexed: 01/06/2024]
Abstract
Tumor cells and surrounding immune cells undergo metabolic reprogramming, leading to an acidic tumor microenvironment. However, it is unclear how tumor cells adapt to this acidic stress during tumor progression. Here we show that carnosine, a mobile buffering metabolite that accumulates under hypoxia in tumor cells, regulates intracellular pH homeostasis and drives lysosome-dependent tumor immune evasion. A previously unrecognized isoform of carnosine synthase, CARNS2, promotes carnosine synthesis under hypoxia. Carnosine maintains intracellular pH (pHi) homeostasis by functioning as a mobile proton carrier to accelerate cytosolic H+ mobility and release, which in turn controls lysosomal subcellular distribution, acidification and activity. Furthermore, by maintaining lysosomal activity, carnosine facilitates nuclear transcription factor X-box binding 1 (NFX1) degradation, triggering galectin-9 and T-cell-mediated immune escape and tumorigenesis. These findings indicate an unconventional mechanism for pHi regulation in cancer cells and demonstrate how lysosome contributes to immune evasion, thus providing a basis for development of combined therapeutic strategies against hepatocellular carcinoma that exploit disrupted pHi homeostasis with immune checkpoint blockade.
Collapse
Affiliation(s)
- Ronghui Yan
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Pinggen Zhang
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- Anhui Province Key Laboratory of Biomedical Aging Research, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- Insitute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, China
| | - Shengqi Shen
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yu Zeng
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Ting Wang
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Zhaolin Chen
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Wenhao Ma
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Junru Feng
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Caixia Suo
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Tong Zhang
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Haoran Wei
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Zetan Jiang
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Rui Chen
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Shi-Ting Li
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiuying Zhong
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Weidong Jia
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Linchong Sun
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
| | - Chunlei Cang
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Huafeng Zhang
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, the First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China.
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China.
- Anhui Province Key Laboratory of Biomedical Aging Research, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China.
- Insitute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, China.
| | - Ping Gao
- Medical Research Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China.
| |
Collapse
|
13
|
Cha S, Min WK, Seo HS. Arabidopsis COP1 guides stomatal response in guard cells through pH regulation. Commun Biol 2024; 7:150. [PMID: 38316905 PMCID: PMC10844630 DOI: 10.1038/s42003-024-05847-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 01/23/2024] [Indexed: 02/07/2024] Open
Abstract
Plants rely on precise regulation of their stomatal pores to effectively carry out photosynthesis while managing water status. The Arabidopsis CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a critical light signaling repressor, is known to repress stomatal opening, but the exact cellular mechanisms remain unknown. Here, we show that COP1 regulates stomatal movement by controlling the pH levels in guard cells. cop1-4 mutants have larger stomatal apertures and disrupted pH dynamics within guard cells, characterized by increased vacuolar and cytosolic pH and reduced apoplastic pH, leading to abnormal stomatal responses. The altered pH profiles are attributed to the increased plasma membrane (PM) H+-ATPase activity of cop1-4 mutants. Moreover, cop1-4 mutants resist to growth defect caused by alkali stress posed on roots. Overall, our study highlights the crucial role of COP1 in maintaining pH homeostasis of guard cells by regulating PM H+-ATPase activity, and demonstrates how proton movement affects stomatal movement and plant growth.
Collapse
Affiliation(s)
- Seoyeon Cha
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Wang Ki Min
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hak Soo Seo
- Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
- Bio-MAX Institute, Seoul National University, Seoul, 08826, Republic of Korea.
| |
Collapse
|
14
|
Gulzar N, Andleeb S, Raza A, Ali S, Liaqat I, Raja SA, Ali NM, Khan R, Awan UA. Acute Toxicity, Anti-diabetic, and Anti-cancerous Potential of Trillium Govanianum-conjugated Silver Nanoparticles in Balb/c Mice. Curr Pharm Biotechnol 2024; 25:1304-1320. [PMID: 37594092 DOI: 10.2174/1389201024666230818124025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/26/2023] [Accepted: 07/20/2023] [Indexed: 08/19/2023]
Abstract
BACKGROUND The current study aimed to develop an economic plant-based therapeutic agent to improve the treatment strategies for diseases at the nano-scale because Cancer and Diabetes mellitus are major concerns in developing countries. Therefore, in vitro and in vivo antidiabetic and anti-cancerous activities of Trillium govanianum conjugated silver nanoparticles were assessed. METHODS In the current study synthesis of silver nanoparticles using Trillium govanianum and characterization were done using a scanning electron microscope, UV-visible spectrophotometer, and FTIR analysis. The in vitro and in vivo anti-diabetic and anti-cancerous potential (200 mg/kg and 400 mg/kg) were carried out. RESULTS It was discovered that Balb/c mice did not show any major alterations during observation of acute oral toxicity when administered orally both TGaqu (1000 mg/kg) and TGAgNPs (1000 mg/kg), and results revealed that 1000 mg/kg is not lethal dose as did not find any abnormalities in epidermal and dermal layers when exposed to TGAgNPs. In vitro studies showed that TGAgNPs could not only inhibit alpha-glucosidase and protein kinases but were also potent against the brine shrimp. Though, a significant reduction in blood glucose levels and significant anti-cancerous effects was recorded when alloxan-treated and CCl4-induced mice were treated with TGAgNPs and TGaqu. CONCLUSION Both in vivo and in vitro studies revealed that TGaqu and TGAgNPs are not toxic at 200 mg/kg, 400 mg/kg, and 1000 mg/kg doses and possess strong anti-diabetic and anti-cancerous effects due to the presence of phyto-constituents. Further, suggesting that green synthesized silver nanoparticles could be used in pharmaceutical industries to develop potent therapeutic agents.
Collapse
Affiliation(s)
- Nazia Gulzar
- Department of Zoology, Microbial Biotechnology Laboratory, University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Pakistan
| | - Saiqa Andleeb
- Department of Zoology, Microbial Biotechnology Laboratory, University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Pakistan
| | - Abida Raza
- PMAS-arid Agriculture University Rawalpindi, Pakistan
| | - Shaukat Ali
- Department of Zoology, Government College University, Lahore, Pakistan
| | - Iram Liaqat
- Department of Zoology, Government College University, Lahore, Pakistan
| | - Sadaf Azad Raja
- Bioscience Department, COMSATS University, Park Road, Chak Shahzad, Islamabad, 44000, Pakistan
| | - Nazish Mazhar Ali
- Department of Zoology, Government College University, Lahore, Pakistan
| | - Rida Khan
- Department of Zoology, Microbial Biotechnology Laboratory, University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Pakistan
| | - Uzma Azeem Awan
- Department of Biological Sciences, National University of Medical Sciences (NUMS), Rawalpindi, Pakistan
| |
Collapse
|
15
|
Charlick JN, Bozadzhieva D, Butler AS, Wilkinson KA, Marrion NV. A single coiled-coil domain mutation in hIKCa channel subunits disrupts preferential formation of heteromeric hSK1:hIKCa channels. Eur J Neurosci 2024; 59:3-16. [PMID: 38018635 PMCID: PMC10952195 DOI: 10.1111/ejn.16189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 09/22/2023] [Accepted: 10/25/2023] [Indexed: 11/30/2023]
Abstract
The expression of IKCa (SK4) channel subunits overlaps with that of SK channel subunits, and it has been proposed that the two related subunits prefer to co-assemble to form heteromeric hSK1:hIKCa channels. This implicates hSK1:hIKCa heteromers in physiological roles that might have been attributed to activation of SK channels. We have used a mutation approach to confirm formation of heterometric hSK1:hIKCa channels. Introduction of residues within hSK1 that were predicted to impart sensitivity to the hIKCa current blocker TRAM-34 changed the pharmacology of functional heteromers. Heteromeric channels formed between wildtype hIKCa and mutant hSK1 subunits displayed a significantly higher sensitivity and maximum block to addition of TRAM-34 than heteromers formed between wildtype subunits. Heteromer formation was disrupted by a single point mutation within one COOH-terminal coiled-coil domain of the hIKCa channel subunit. This mutation only disrupted the formation of hSK1:hIKCa heteromeric channels, without affecting the formation of homomeric hIKCa channels. Finally, the Ca2+ gating sensitivity of heteromeric hSK1:hIKCa channels was found to be significantly lower than the Ca2+ gating sensitivity of homomeric hIKCa channels. These data confirmed the preferred formation of heteromeric channels that results from COOH-terminal interactions between subunits. The distinct sensitivity of the heteromer to activation by Ca2+ suggests that heteromeric channels fulfil a distinct function within those neurons that express both subunits.
Collapse
Affiliation(s)
- James N. Charlick
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Daniella Bozadzhieva
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Andrew S. Butler
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Kevin A. Wilkinson
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Neil V. Marrion
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| |
Collapse
|
16
|
Abstract
Cancers undergo sequential changes to proton (H+) concentration and sensing that are consequences of the disease and facilitate its further progression. The impact of protonation state on protein activity can arise from alterations to amino acids or their titration. Indeed, many cancer-initiating mutations influence pH balance, regulation or sensing in a manner that enables growth and invasion outside normal constraints as part of oncogenic transformation. These cancer-supporting effects become more prominent when tumours develop an acidic microenvironment owing to metabolic reprogramming and disordered perfusion. The ensuing intracellular and extracellular pH disturbances affect multiple aspects of tumour biology, ranging from proliferation to immune surveillance, and can even facilitate further mutagenesis. As a selection pressure, extracellular acidosis accelerates disease progression by favouring acid-resistant cancer cells, which are typically associated with aggressive phenotypes. Although acid-base disturbances in tumours often occur alongside hypoxia and lactate accumulation, there is now ample evidence for a distinct role of H+-operated responses in key events underpinning cancer. The breadth of these actions presents therapeutic opportunities to change the trajectory of disease.
Collapse
Affiliation(s)
- Pawel Swietach
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
| | - Stine Falsig Pedersen
- Department of Biology, University of Copenhagen, University of Copenhagen, Faculty of Science, København, Denmark.
| |
Collapse
|
17
|
Abstract
In attempts to simulate the protonation of proteins, a major challenge is that the number of protonation states grows rapidly as a function (2N) of the number of protonation sites (N). Expression on the free energy of the protonation state as an N-site Ising model ─ using an empirical Generalized-Born model ─ allows a quantum computer to efficiently determine the important states at a given pH value and subsequently reconstruct the pH titration process at all sites. Compared with the exact results painstakingly obtained with classical computers, the results obtained using quantum computers show good agreement for staphylococcal nuclease and excellent agreement for α-lactalbumin. This work illustrates the effectiveness of quantum computers in sampling important physical states, which may be useful in attacking challenging biomolecular problems.
Collapse
Affiliation(s)
- Hao Hu
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Polaris Quantum Biotech Inc., Suite 205, 201 W Main St., Durham, North Carolina 27701, United States
| |
Collapse
|
18
|
Kapur B, Baldessari F, Lazaratos M, Nar H, Schnapp G, Giorgetti A, Bondar AN. Protons taken hostage: Dynamic H-bond networks of the pH-sensing GPR68. Comput Struct Biotechnol J 2023; 21:4370-4384. [PMID: 37711190 PMCID: PMC10498176 DOI: 10.1016/j.csbj.2023.08.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/16/2023] Open
Abstract
Proton-sensing G Protein Coupled Receptors (GPCRs) sense changes in the extracellular pH to effect cell signaling for cellular homeostasis. They tend to be overexpressed in solid tumors associated with acidic extracellular pH, and are of direct interest as drug targets. How proton-sensing GPCRs sense extracellular acidification and activate upon protonation change is important to understand, because it may guide the design of therapeutics. Lack of publicly available experimental structures make it challenging to discriminate between conflicting mechanisms proposed for proton-binding, as main roles have been assigned to either an extracellular histidine cluster or to an internal carboxylic triad. Here we present a protocol to derive and evaluate structural models of the proton-sensing GPR68. This approach integrates state-of-the-art homology modeling with microsecond-timescale atomistic simulations, and with a detailed assessment of the compatibility of the structural models with known structural features of class A GPCRs. To decipher structural elements of potential interest for protonation-coupled conformational changes of GPR68, we used the best-compatible model as a starting point for independent atomistic simulations of GPR68 with different protonation states, and graph computations to characterize the response of GPR68 to changes in protonation. We found that GPR68 hosts an extended hydrogen-bond network that inter-connects the extracellular histidine cluster to the internal carboxylic triad, and which can even reach groups at the cytoplasmic G-protein binding site. Taken together, results suggest that GPR68 relies on dynamic, hydrogen-bond networks to inter-connect extracellular and internal proton-binding sites, and to elicit conformational changes at the cytoplasmic G-protein binding site.
Collapse
Affiliation(s)
- Bhav Kapur
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Birkendorfer Straße 65, 88397 Biberach an der Riß, Germany
- Christian-Albrechts-University of Kiel, 24118 Kiel, Germany
| | | | - Michalis Lazaratos
- Department of Physics, Theoretical Molecular Biophysics Group, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Herbert Nar
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Birkendorfer Straße 65, 88397 Biberach an der Riß, Germany
| | - Gisela Schnapp
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Birkendorfer Straße 65, 88397 Biberach an der Riß, Germany
| | - Alejandro Giorgetti
- University of Verona, Department of Biotechnology, 37134 Verona, Italy
- Forschungszentrum Jülich, Institute for Neuroscience and Medicine and Institute for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Wilhelm-Johnen Straße, 52525 Jülich, Germany
| | - Ana-Nicoleta Bondar
- Forschungszentrum Jülich, Institute for Neuroscience and Medicine and Institute for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Wilhelm-Johnen Straße, 52525 Jülich, Germany
- University of Bucharest, Faculty of Physics, Str. Atomiştilor 405, 077125 Bucharest-Măgurele, Romania
| |
Collapse
|
19
|
Liu Y, Reyes E, Castillo-Azofeifa D, Klein OD, Nystul T, Barber DL. Intracellular pH dynamics regulates intestinal stem cell lineage specification. Nat Commun 2023; 14:3745. [PMID: 37353491 PMCID: PMC10290085 DOI: 10.1038/s41467-023-39312-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 06/06/2023] [Indexed: 06/25/2023] Open
Abstract
Intracellular pH dynamics is increasingly recognized to regulate myriad cell behaviors. We report a finding that intracellular pH dynamics also regulates adult stem cell lineage specification. We identify an intracellular pH gradient in mouse small intestinal crypts, lowest in crypt stem cells and increasing along the crypt column. Disrupting this gradient by inhibiting H+ efflux by Na+/H+ exchanger 1 abolishes crypt budding and blocks differentiation of Paneth cells, which are rescued with exogenous WNT. Using single-cell RNA sequencing and lineage tracing we demonstrate that intracellular pH dynamics acts downstream of ATOH1, with increased pH promoting differentiation toward the secretory lineage. Our findings indicate that an increase in pH is required for the lineage specification that contributes to crypt maintenance, establishing a role for intracellular pH dynamics in cell fate decisions within an adult stem cell lineage.
Collapse
Affiliation(s)
- Yi Liu
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Efren Reyes
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, 94143, USA
| | - David Castillo-Azofeifa
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, 94143, USA
- Immunology Discovery, Genentech, Inc., South San Francisco, CA, 94080, USA
| | - Ophir D Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Todd Nystul
- Departments of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA.
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA, 94143, USA.
| |
Collapse
|
20
|
Yang Y, Gao Z, Yang D. pH-dependent self-assembly mechanism of a single repetitive domain from a spider silk protein. Int J Biol Macromol 2023; 242:124775. [PMID: 37169045 DOI: 10.1016/j.ijbiomac.2023.124775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
Spider silk is self-assembled from full-length silk proteins, and some silk protein fragments can also form silk-like fibers in vitro. However, the mechanism underlying the silk fiber formation is not understood well. In this study, we investigated the fiber formation of a single repetitive domain (RP) from a minor ampullate silk protein (MiSp). Our findings revealed that pH and salt concentration affect not only the stability of MiSp-RP but also its self-assembly into fibers and aggregates. Using nuclear magnetic resonance (NMR) spectroscopy, we solved the three-dimensional (3D) structure of MiSp RP in aqueous solution. On the basis of the structure and mutagenesis, we revealed that charge-dipole interactions are responsible for the pH- and salt-dependent properties of MiSp-RP. Our results indicate that fiber formation is regulated by a delicate balance between intermolecular and intramolecular interactions, rather than by the protein stability alone. These findings have implications for the design of silk proteins for mass production of spider silk.
Collapse
Affiliation(s)
- Yadi Yang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Zhenwei Gao
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Daiwen Yang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore.
| |
Collapse
|
21
|
Schulte T, Panas MD, Han X, Williams L, Kedersha N, Fleck JS, Tan TJC, Dopico XC, Olsson A, Morro AM, Hanke L, Nilvebrant J, Giang KA, Nygren PÅ, Anderson P, Achour A, McInerney GM. Caprin-1 binding to the critical stress granule protein G3BP1 is influenced by pH. Open Biol 2023; 13:220369. [PMID: 37161291 PMCID: PMC10170197 DOI: 10.1098/rsob.220369] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/28/2023] [Indexed: 05/11/2023] Open
Abstract
G3BP is the central node within stress-induced protein-RNA interaction networks known as stress granules (SGs). The SG-associated proteins Caprin-1 and USP10 bind mutually exclusively to the NTF2 domain of G3BP1, promoting and inhibiting SG formation, respectively. Herein, we present the crystal structure of G3BP1-NTF2 in complex with a Caprin-1-derived short linear motif (SLiM). Caprin-1 interacts with His-31 and His-62 within a third NTF2-binding site outside those covered by USP10, as confirmed using biochemical and biophysical-binding assays. Nano-differential scanning fluorimetry revealed reduced thermal stability of G3BP1-NTF2 at acidic pH. This destabilization was counterbalanced significantly better by bound USP10 than Caprin-1. The G3BP1/USP10 complex immunoprecipated from human U2OS cells was more resistant to acidic buffer washes than G3BP1/Caprin-1. Acidification of cellular condensates by approximately 0.5 units relative to the cytosol was detected by ratiometric fluorescence analysis of pHluorin2 fused to G3BP1. Cells expressing a Caprin-1/FGDF chimera with higher G3BP1-binding affinity had reduced Caprin-1 levels and slightly reduced condensate sizes. This unexpected finding may suggest that binding of the USP10-derived SLiM to NTF2 reduces the propensity of G3BP1 to enter condensates.
Collapse
Affiliation(s)
- Tim Schulte
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, and Division of Infectious Diseases, Karolinska University Hospital, Stockholm, 171 77, Sweden
| | - Marc D. Panas
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Xiao Han
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, and Division of Infectious Diseases, Karolinska University Hospital, Stockholm, 171 77, Sweden
| | - Lucy Williams
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Nancy Kedersha
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Jonas Simon Fleck
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, and Division of Infectious Diseases, Karolinska University Hospital, Stockholm, 171 77, Sweden
| | - Timothy J. C. Tan
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Xaquin Castro Dopico
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Anders Olsson
- Protein Expression and Characterization, AlbaNova University Center, Royal Institute of Technology, 114 21, Stockholm
| | - Ainhoa Moliner Morro
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Leo Hanke
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Johan Nilvebrant
- Division of Protein Engineering, Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology, 114 21, Stockholm
- Science for Life Laboratory, Tomtebodavägen 23A, 171 65, Sweden
| | - Kim Anh Giang
- Division of Protein Engineering, Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology, 114 21, Stockholm
- Science for Life Laboratory, Tomtebodavägen 23A, 171 65, Sweden
| | - Per-Åke Nygren
- Division of Protein Engineering, Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology, 114 21, Stockholm
- Science for Life Laboratory, Tomtebodavägen 23A, 171 65, Sweden
| | - Paul Anderson
- Division of Rheumatology, Immunity, and Inflammation, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Harvard Medical School Initiative for RNA Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, and Division of Infectious Diseases, Karolinska University Hospital, Stockholm, 171 77, Sweden
| | - Gerald M. McInerney
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| |
Collapse
|
22
|
Zhou J, Yan X, Liu Y, Yang J. Succinylation of CTBP1 mediated by KAT2A suppresses its inhibitory activity on the transcription of CDH1 to promote the progression of prostate cancer. Biochem Biophys Res Commun 2023; 650:9-16. [PMID: 36764210 DOI: 10.1016/j.bbrc.2023.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/05/2023]
Abstract
CTBP1 has been demonstrated as a co-repressor in the transcriptional regulation of downstream genes and is involved in various cell process. However, the mechanism of CTBP1 in the progression of prostate cancer is still unclear. Here, we aim to investigate how CTBP1 exerts its role in prostate cancer progression, especially how CTBP1 was regulated by the upstream genes. We found that CTBP1 was highly expressed in prostate cancer and promoted the cell viability, migration, invasion and glycolysis of prostate cancer cells. CDH1 was verified to be the target of CTBP1. We determined that CTBP1 could directly bind with SP1 to inhibit the transcription of CDH1. Moreover, succinylation of CTBP1 was found to be up-regulated in prostate cancer cell. Further studies demonstrated that KAT2A promotes the succinylation of CTBP1 and mediates the transcription suppressing activity of it. In addition, the K46 and K280 was confirmed to be the two sites that regulated by KAT2A. In vivo studies further indicated that CTBP1 could promote the growth of prostate cancer, and this effect of CTBP1 could be partially reversed by KAT2A knockdown. Taken together, we found that succinylation of CTBP1 mediated by KAT2A suppresses the inhibitory activity of CTBP1 on the transcription of CDH1, thus act as an oncogene.
Collapse
Affiliation(s)
- Jinmeng Zhou
- Department of Geriatrics, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; Department of Critical Care Medicine, The First Hospital of Shanxi Medical University, Taiyuan, China
| | - Xiaoting Yan
- Department of Urology, The First Hospital of Shanxi Medical University, Taiyuan, China
| | - Ying Liu
- Department of Geriatrics,Beijing Jishuitan Hospital, Beijing, China
| | - Jihong Yang
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China; Department of Nephrology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Science, Beijing, China.
| |
Collapse
|
23
|
De Rosa A, McGaughey S, Magrath I, Byrt C. Molecular membrane separation: plants inspire new technologies. THE NEW PHYTOLOGIST 2023; 238:33-54. [PMID: 36683439 DOI: 10.1111/nph.18762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Plants draw up their surrounding soil solution to gain water and nutrients required for growth, development and reproduction. Obtaining adequate water and nutrients involves taking up both desired and undesired elements from the soil solution and separating resources from waste. Desirable and undesirable elements in the soil solution can share similar chemical properties, such as size and charge. Plants use membrane separation mechanisms to distinguish between different molecules that have similar chemical properties. Membrane separation enables distribution or retention of resources and efflux or compartmentation of waste. Plants use specialised membrane separation mechanisms to adapt to challenging soil solution compositions and distinguish between resources and waste. Coordination and regulation of these mechanisms between different tissues, cell types and subcellular membranes supports plant nutrition, environmental stress tolerance and energy management. This review considers membrane separation mechanisms in plants that contribute to specialised separation processes and highlights mechanisms of interest for engineering plants with enhanced performance in challenging conditions and for inspiring the development of novel industrial membrane separation technologies. Knowledge gained from studying plant membrane separation mechanisms can be applied to developing precision separation technologies. Separation technologies are needed for harvesting resources from industrial wastes and transitioning to a circular green economy.
Collapse
Affiliation(s)
- Annamaria De Rosa
- Division of Plant Science, Research School of Biology, Australian National University, 2601, ACT, Acton, Australia
| | - Samantha McGaughey
- Division of Plant Science, Research School of Biology, Australian National University, 2601, ACT, Acton, Australia
| | - Isobel Magrath
- Division of Plant Science, Research School of Biology, Australian National University, 2601, ACT, Acton, Australia
| | - Caitlin Byrt
- Division of Plant Science, Research School of Biology, Australian National University, 2601, ACT, Acton, Australia
| |
Collapse
|
24
|
Fredericks AM, East KW, Shi Y, Liu J, Maschietto F, Ayala A, Cioffi WG, Cohen M, Fairbrother WG, Lefort CT, Nau GJ, Levy MM, Wang J, Batista VS, Lisi GP, Monaghan SF. Identification and mechanistic basis of non-ACE2 blocking neutralizing antibodies from COVID-19 patients with deep RNA sequencing and molecular dynamics simulations. Front Mol Biosci 2022; 9:1080964. [PMID: 36589229 PMCID: PMC9800910 DOI: 10.3389/fmolb.2022.1080964] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
Variants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continue to cause disease and impair the effectiveness of treatments. The therapeutic potential of convergent neutralizing antibodies (NAbs) from fully recovered patients has been explored in several early stages of novel drugs. Here, we identified initially elicited NAbs (Ig Heavy, Ig lambda, Ig kappa) in response to COVID-19 infection in patients admitted to the intensive care unit at a single center with deep RNA sequencing (>100 million reads) of peripheral blood as a diagnostic tool for predicting the severity of the disease and as a means to pinpoint specific compensatory NAb treatments. Clinical data were prospectively collected at multiple time points during ICU admission, and amino acid sequences for the NAb CDR3 segments were identified. Patients who survived severe COVID-19 had significantly more of a Class 3 antibody (C135) to SARS-CoV-2 compared to non-survivors (15059.4 vs. 1412.7, p = 0.016). In addition to highlighting the utility of RNA sequencing in revealing unique NAb profiles in COVID-19 patients with different outcomes, we provided a physical basis for our findings via atomistic modeling combined with molecular dynamics simulations. We established the interactions of the Class 3 NAb C135 with the SARS-CoV-2 spike protein, proposing a mechanistic basis for inhibition via multiple conformations that can effectively prevent ACE2 from binding to the spike protein, despite C135 not directly blocking the ACE2 binding motif. Overall, we demonstrate that deep RNA sequencing combined with structural modeling offers the new potential to identify and understand novel therapeutic(s) NAbs in individuals lacking certain immune responses due to their poor endogenous production. Our results suggest a possible window of opportunity for administration of such NAbs when their full sequence becomes available. A method involving rapid deep RNA sequencing of patients infected with SARS-CoV-2 or its variants at the earliest infection time could help to develop personalized treatments using the identified specific NAbs.
Collapse
Affiliation(s)
- Alger M. Fredericks
- Department of Surgery, Division of Surgical Research, The Miriam Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Kyle W. East
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Yuanjun Shi
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | | | - Alfred Ayala
- Department of Surgery, Division of Surgical Research, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| | - William G. Cioffi
- Department of Surgery, Division of Surgical Research, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| | - Maya Cohen
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| | - William G. Fairbrother
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Craig T. Lefort
- Department of Surgery, Division of Surgical Research, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| | - Gerard J. Nau
- Department of Medicine, Division of Infectious Disease, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| | - Mitchell M. Levy
- Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Victor S. Batista
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - George P. Lisi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Sean F. Monaghan
- Department of Surgery, Division of Surgical Research, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, United States
| |
Collapse
|
25
|
Weigle AT, Feng J, Shukla D. Thirty years of molecular dynamics simulations on posttranslational modifications of proteins. Phys Chem Chem Phys 2022; 24:26371-26397. [PMID: 36285789 PMCID: PMC9704509 DOI: 10.1039/d2cp02883b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Posttranslational modifications (PTMs) are an integral component to how cells respond to perturbation. While experimental advances have enabled improved PTM identification capabilities, the same throughput for characterizing how structural changes caused by PTMs equate to altered physiological function has not been maintained. In this Perspective, we cover the history of computational modeling and molecular dynamics simulations which have characterized the structural implications of PTMs. We distinguish results from different molecular dynamics studies based upon the timescales simulated and analysis approaches used for PTM characterization. Lastly, we offer insights into how opportunities for modern research efforts on in silico PTM characterization may proceed given current state-of-the-art computing capabilities and methodological advancements.
Collapse
Affiliation(s)
- Austin T Weigle
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jiangyan Feng
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| |
Collapse
|
26
|
Differential trafficking of ligands trogocytosed via CD28 versus CTLA4 promotes collective cellular control of co-stimulation. Nat Commun 2022; 13:6459. [PMID: 36309492 PMCID: PMC9617924 DOI: 10.1038/s41467-022-34156-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 10/14/2022] [Indexed: 12/25/2022] Open
Abstract
Intercellular communication is crucial for collective regulation of cellular behaviors. While clustering T cells have been shown to mutually control the production of key communication signals, it is unclear whether they also jointly regulate their availability and degradation. Here we use newly developed reporter systems, bioinformatic analyses, protein structure modeling and genetic perturbations to assess this. We find that T cells utilize trogocytosis by competing antagonistic receptors to differentially control the abundance of immunoregulatory ligands. Specifically, ligands trogocytosed via CD28 are shuttled to the T cell surface, enabling them to co-stimulate neighboring T cells. In contrast, CTLA4-mediated trogocytosis targets ligands for degradation. Mechanistically, this fate separation is controlled by different acid-sensitivities of receptor-ligand interactions and by the receptor intracellular domains. The ability of CD28 and CTLA4 to confer different fates to trogocytosed ligands reveals an additional layer of collective regulation of cellular behaviors and promotes the robustness of population dynamics.
Collapse
|
27
|
Wang N, Zhou L, Shao CY, Wang XT, Zhang N, Ma J, Hu HL, Wang Y, Qiu M, Shen Y. Potassium channel K ir 4.1 regulates oligodendrocyte differentiation via intracellular pH regulation. Glia 2022; 70:2093-2107. [PMID: 35775976 DOI: 10.1002/glia.24240] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 06/06/2022] [Accepted: 06/24/2022] [Indexed: 11/10/2022]
Abstract
In humans, loss-of-function mutations of Kcnj10 in SeSAME/EAST syndrome, which encodes the inwardly rectifying K+ channel 4.1 (Kir 4.1), causes progressive neurological decline. Despite its rich expression in oligodendrocyte (OL) lineage cells and an emerging link with demyelinating disease, the function of Kir 4.1 in OLs is unclear. Here we show a novel role of Kir 4.1 in OL development. Kir 4.1 expression is markedly greater in OLs than in OL precursor cells (OPCs), and the down-regulation of Kir 4.1 impairs OL maturation by affecting OPC differentiation. Interestingly, Kir 4.1 regulates the intracellular pH of OPCs and OLs via the Na+ /H+ exchanger, which underlies impeded OPC differentiation by Kir 4.1 inhibition. Furthermore, Kir 4.1 regulates GSK3β and SOX10, two molecules critical to OPC development. Collectively, our work opens a new avenue to understanding the functions of Kir 4.1 and intracellular pH in OLs.
Collapse
Affiliation(s)
- Na Wang
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Liang Zhou
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Brain Science, Guizhou Institution of Higher Education, Zunyi Medical University, Zunyi, China
| | - Chong-Yu Shao
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xin-Tai Wang
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Nan Zhang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Jiao Ma
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Hai-Lan Hu
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China
| | - Yin Wang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Mengsheng Qiu
- Institute of Life Sciences, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Ying Shen
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
28
|
Raja JAJ, Huang C, Chen C, Hu W, Cheng H, Goh R, Chao C, Tan Y, Yeh S. Modification of the N-terminal FWKG-αH1 element of potyviral HC-Pro affects its multiple functions and generates effective attenuated mutants for cross-protection. MOLECULAR PLANT PATHOLOGY 2022; 23:947-965. [PMID: 35285990 PMCID: PMC9190983 DOI: 10.1111/mpp.13201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 06/01/2023]
Abstract
Control of plant viruses by cross-protection is limited by the availability of effective protective strains. Incorporation of an NIa-protease processing site in the extreme N-terminal region of the helper component protease (HC-Pro) of turnip mosaic virus (TuMV) resulted in a mutant virus TuHND I that induced highly attenuated symptoms. Recombination analysis verified that two variations, F7I mutation and amino acid 7-upstream-deletion, in HC-Pro co-determined TuHND I attenuation. TuHND I provided complete protection to Nicotiana benthamiana and Brassica campestris subsp. chinensis plants against infection by the severe parental strain. Aphid transmission tests revealed that TuHND I was not aphid-transmissible. An RNA silencing suppression (RSS) assay by agroinfiltration suggested the RSS-defective nature of the mutant HC-Pro. In the context (amino acids 3-17) encompassing the two variations of HC-Pro, we uncovered an FWKG-α-helix 1 (αH1) element that influenced the functions of aphid transmission and RSS, whose motifs were located far downstream. We further demonstrated that HC-Pro F7 was a critical residue on αH1 for HC-Pro functions and that reinstating αH1 in the RSS-defective HC-Pro of TuHND I restored the protein's RSS function. Yeast two-hybrid and bimolecular fluorescence complementation assays indicated the FWKG-αH1 element as an integral part of the HC-Pro self-interaction domain. The possibility of regulation of the mechanistically independent functions of RSS and aphid transmission by the FWKG-αH1 element is discussed. Extension of TuMV HC-Pro FWKG-αH1 variations to another potyvirus, zucchini yellow mosaic virus, also generated nonaphid-transmissible cross-protective mutant viruses. Hence, the modification of the FWKG-αH1 element can generate effective attenuated viruses for the control of potyviruses by cross-protection.
Collapse
Affiliation(s)
- Joseph A. J. Raja
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
- Advanced Plant Biotechnology CenterNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| | - Chung‐Hao Huang
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| | - Chin‐Chih Chen
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
- Division of Plant PathologyTaiwan Agricultural Research InstituteWu‐FengTaichungTaiwan, R.O.C.
| | - Wen‐Chi Hu
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| | - Hao‐Wen Cheng
- Advanced Plant Biotechnology CenterNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| | - Reun‐Ping Goh
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| | - Chia‐Hung Chao
- Taichung District Agricultural Research and Extension StationDacunChanghua CountyTaiwan, R.O.C.
| | - Yue‐Rong Tan
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| | - Shyi‐Dong Yeh
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
- Advanced Plant Biotechnology CenterNational Chung Hsing UniversityTaichungTaiwan, R.O.C.
| |
Collapse
|
29
|
MacKenzie DWS, Schaefer A, Steckner J, Leo CA, Naser D, Artikis E, Broom A, Ko T, Shah P, Ney MQ, Tran E, Smith MTJ, Fuglestad B, Wand AJ, Brooks CL, Meiering EM. A fine balance of hydrophobic-electrostatic communication pathways in a pH-switching protein. Proc Natl Acad Sci U S A 2022; 119:e2119686119. [PMID: 35737838 PMCID: PMC9245636 DOI: 10.1073/pnas.2119686119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/29/2022] [Indexed: 12/24/2022] Open
Abstract
Allostery is the phenomenon of coupling between distal binding sites in a protein. Such coupling is at the crux of protein function and regulation in a myriad of scenarios, yet determining the molecular mechanisms of coupling networks in proteins remains a major challenge. Here, we report mechanisms governing pH-dependent myristoyl switching in monomeric hisactophilin, whereby the myristoyl moves between a sequestered state, i.e., buried within the core of the protein, to an accessible state, in which the myristoyl has increased accessibility for membrane binding. Measurements of the pH and temperature dependence of amide chemical shifts reveal protein local structural stability and conformational heterogeneity that accompany switching. An analysis of these measurements using a thermodynamic cycle framework shows that myristoyl-proton coupling at the single-residue level exists in a fine balance and extends throughout the protein. Strikingly, small changes in the stereochemistry or size of core and surface hydrophobic residues by point mutations readily break, restore, or tune myristoyl switch energetics. Synthesizing the experimental results with those of molecular dynamics simulations illuminates atomistic details of coupling throughout the protein, featuring a large network of hydrophobic interactions that work in concert with key electrostatic interactions. The simulations were critical for discerning which of the many ionizable residues in hisactophilin are important for switching and identifying the contributions of nonnative interactions in switching. The strategy of using temperature-dependent NMR presented here offers a powerful, widely applicable way to elucidate the molecular mechanisms of allostery in proteins at high resolution.
Collapse
Affiliation(s)
| | - Anna Schaefer
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Julia Steckner
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Christopher A. Leo
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Dalia Naser
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Efrosini Artikis
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109
| | - Aron Broom
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Travis Ko
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Purnank Shah
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Mikaela Q. Ney
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Elisa Tran
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Martin T. J. Smith
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Brian Fuglestad
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - A. Joshua Wand
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Charles L. Brooks
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109
| | | |
Collapse
|
30
|
Lazaratos M, Siemers M, Brown LS, Bondar AN. Conserved hydrogen-bond motifs of membrane transporters and receptors. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183896. [PMID: 35217000 DOI: 10.1016/j.bbamem.2022.183896] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/04/2022] [Accepted: 02/16/2022] [Indexed: 01/18/2023]
Abstract
Membrane transporters and receptors often rely on conserved hydrogen bonds to assemble transient paths for ion transfer or long-distance conformational couplings. For transporters and receptors that use proton binding and proton transfer for function, inter-helical hydrogen bonds of titratable protein sidechains that could change protonation are of central interest to formulate hypotheses about reaction mechanisms. Knowledge of hydrogen bonds common at sites of potential interest for proton binding could thus inform and guide studies on functional mechanisms of protonation-coupled membrane proteins. Here we apply graph-theory approaches to identify hydrogen-bond motifs of carboxylate and histidine sidechains in a large data set of static membrane protein structures. We find that carboxylate-hydroxyl hydrogen bonds are present in numerous structures of the dataset, and can be part of more extended H-bond clusters that could be relevant to conformational coupling. Carboxylate-carboxyamide and imidazole-imidazole hydrogen bonds are represented in comparably fewer protein structures of the dataset. Atomistic simulations on two membrane transporters in lipid membranes suggest that many of the hydrogen bond motifs present in static protein structures tend to be robust, and can be part of larger hydrogen-bond clusters that recruit additional hydrogen bonds.
Collapse
Affiliation(s)
- Michalis Lazaratos
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| | - Malte Siemers
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| | - Leonid S Brown
- University of Guelph, Department of Physics, 50 Stone Road E., Guelph, Ontario N1G 2W1, Canada
| | - Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany; University of Bucharest, Faculty of Physics, Atomiștilor 405, Măgurele 077125, Romania; Forschungszentrum Jülich, Institute for Neuroscience and Medicine and Institute for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Wilhelm-Johnen Straße, 52428 Jülich, Germany.
| |
Collapse
|
31
|
Schmitz M, Schultze A, Vanags R, Voigt K, Di Ventura B, Öztürk MA. patcHwork: a user-friendly pH sensitivity analysis web server for protein sequences and structures. Nucleic Acids Res 2022; 50:W560-W567. [PMID: 35438792 PMCID: PMC9252814 DOI: 10.1093/nar/gkac252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/11/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022] Open
Abstract
pH regulates protein function and interactions by altering the charge of individual residues causing loss or gain of intramolecular noncovalent bonds, which may lead to structural rearrangements. While tools to analyze residue-specific charge distribution of proteins at a given pH exist, currently no tool is available to investigate noncovalent bond changes at two different pH values. To make protein pH sensitivity analysis more accessible, we developed patcHwork, a web server that combines the identification of amino acids undergoing a charge shift with the determination of affected noncovalent bonds at two user-defined pH values. At the sequence-only level, patcHwork applies the Henderson–Hasselbalch equation to determine pH-sensitive residues. When the 3D protein structure is available, patcHwork can be employed to gain mechanistic understanding of the effect of pH. This is achieved using the PDB2PQR and PROPKA tools and noncovalent bond determination algorithms. A user-friendly interface allows visualizing pH-sensitive residues, affected salt bridges, hydrogen bonds and aromatic (pi–pi and cation–pi) interactions. patcHwork can be used to identify patches, a new concept we propose of pH-sensitive residues in close proximity on the protein, which may have a major impact on function. We demonstrate the attractiveness of patcHwork studying experimentally investigated pH-sensitive proteins (https://patchwork.biologie.uni-freiburg.de/).
Collapse
Affiliation(s)
- Mirko Schmitz
- Signaling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany.,Institute of Biology II, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Anne Schultze
- Signaling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany.,Institute of Biology II, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Raimonds Vanags
- Institute of Biology III, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Karsten Voigt
- Institute of Biology III, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Barbara Di Ventura
- Signaling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany.,Institute of Biology II, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Mehmet Ali Öztürk
- Signaling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany.,Institute of Biology II, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| |
Collapse
|
32
|
Chan MC, Procko E, Shukla D. Structural Rearrangement of the Serotonin Transporter Intracellular Gate Induced by Thr276 Phosphorylation. ACS Chem Neurosci 2022; 13:933-945. [PMID: 35258286 DOI: 10.1021/acschemneuro.1c00714] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The reuptake of the neurotransmitter serotonin from the synaptic cleft by the serotonin transporter, SERT, is essential for proper neurological signaling. Biochemical studies have shown that Thr276 of transmembrane helix 5 is a site of PKG-mediated SERT phosphorylation, which has been proposed to shift the SERT conformational equilibria to promote inward-facing states, thus enhancing 5-HT transport. Recent structural and simulation studies have provided insights into the conformation transitions during substrate transport but have not shed light on SERT regulation via post-translational modifications. Using molecular dynamics simulations and Markov state models, we investigate how Thr276 phosphorylation impacts the SERT mechanism and its role in enhancing transporter stability and function. Our simulations show that Thr276 phosphorylation alters the hydrogen-bonding network involving residues on transmembrane helix 5. This in turn decreases the free energy barriers for SERT to transition to the inward-facing state, thus facilitating 5-HT import. The results provide atomistic insights into in vivo SERT regulation and can be extended to other pharmacologically important transporters in the solute carrier family.
Collapse
Affiliation(s)
- Matthew C. Chan
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Erik Procko
- Department of Biochemistry, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Neuroscience Program, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- National Center for Supercomputing Applications, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
33
|
Li X, Fan JS, Shi M, Lai CC, Li J, Meng Q, Yang D. C-Terminal Domains of Spider Silk Proteins Having Divergent Structures but Conserved Functional Roles. Biomacromolecules 2022; 23:1643-1651. [PMID: 35312302 DOI: 10.1021/acs.biomac.1c01513] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Spider silk is self-assembled from silk proteins or spidroins. C-terminal domains (CTDs) of various types of spidroins are relatively conserved in amino acid sequences and are suggested to adopt similar structures and perform similar functional roles in spidroin storage and silk formation. Here, we solved the structure of the CTD from a capture-spiral silk protein (CTDFl) and characterized its stability and fibril formation in the presence and absence of a reducing agent at different pH values. CTDFl adopts a dimeric structure with 8 helices, but the CTDs of other types of spidroins exist in a domain-swapped dimeric structure with 10 helices. Despite the structural differences, CTDFl is pH-responsive in stability and fibril formation, similar to the CTDs from minor and major ampullate spidroins. Thus, the functional role of CTDs in silk fiber formation seems conserved. Comparing wild-type CTDFl and its mutants, we found that the pH-responsive behavior results from the protonation of H76, which is conserved from different spider species. In addition, the fibril formation rate of CTDFl correlates with its instability, suggesting that structural changes are involved in fibril formation.
Collapse
Affiliation(s)
- Xue Li
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.,College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, P. R. China
| | - Jing-Song Fan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Mengqi Shi
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Chong Cheong Lai
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Jiaxin Li
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Qing Meng
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, P. R. China
| | - Daiwen Yang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| |
Collapse
|
34
|
Liu G, Tan J, Cen J, Zhang G, Hu J, Liu S. Oscillating the local milieu of polymersome interiors via single input-regulated bilayer crosslinking and permeability tuning. Nat Commun 2022; 13:585. [PMID: 35102153 PMCID: PMC8803951 DOI: 10.1038/s41467-022-28227-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 12/31/2021] [Indexed: 11/09/2022] Open
Abstract
The unique permselectivity of cellular membranes is of crucial importance to maintain intracellular homeostasis while adapting to microenvironmental changes. Although liposomes and polymersomes have been widely engineered to mimic microstructures and functions of cells, it still remains a considerable challenge to synergize the stability and permeability of artificial cells and to imitate local milieu fluctuations. Herein, we report concurrent crosslinking and permeabilizing of pH-responsive polymersomes containing Schiff base moieties within bilayer membranes via enzyme-catalyzed acid production. Notably, this synergistic crosslinking and permeabilizing strategy allows tuning of the mesh sizes of the crosslinked bilayers with subnanometer precision, showing discriminative permeability toward maltooligosaccharides with molecular sizes of ~1.4-2.6 nm. The permselectivity of bilayer membranes enables intravesicular pH oscillation, fueled by a single input of glucose. This intravesicular pH oscillation can further drive the dissipative self-assembly of pH-sensitive dipeptides. Moreover, the permeabilization of polymersomes can be regulated by intracellular pH gradient as well, enabling the controlled release of encapsulated payloads.
Collapse
Affiliation(s)
- Guhuan Liu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, 230026, Hefei, Anhui, China
| | - Jiajia Tan
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, 230026, Hefei, Anhui, China
| | - Jie Cen
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, 230026, Hefei, Anhui, China
| | - Guoying Zhang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, 230026, Hefei, Anhui, China
| | - Jinming Hu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, 230026, Hefei, Anhui, China.
| | - Shiyong Liu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, 230026, Hefei, Anhui, China.
| |
Collapse
|
35
|
Bondar AN. Mechanisms of long-distance allosteric couplings in proton-binding membrane transporters. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 128:199-239. [PMID: 35034719 DOI: 10.1016/bs.apcsb.2021.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Membrane transporters that use proton binding and proton transfer for function couple local protonation change with changes in protein conformation and water dynamics. Changes of protein conformation might be required to allow transient formation of hydrogen-bond networks that bridge proton donor and acceptor pairs separated by long distances. Inter-helical hydrogen-bond networks adjust rapidly to protonation change, and ensure rapid response of the protein structure and dynamics. Membrane transporters with known three-dimensional structures and proton-binding groups inform on general principles of protonation-coupled protein conformational dynamics. Inter-helical hydrogen bond motifs between proton-binding carboxylate groups and a polar sidechain are observed in unrelated membrane transporters, suggesting common principles of coupling protonation change with protein conformational dynamics.
Collapse
Affiliation(s)
- Ana-Nicoleta Bondar
- University of Bucharest, Faculty of Physics, Măgurele, Romania; Forschungszentrum Jülich, Institute of Computational Biomedicine, Jülich, Germany.
| |
Collapse
|
36
|
Understanding metabolic alterations and heterogeneity in cancer progression through validated immunodetection of key molecular components: a case of carbonic anhydrase IX. Cancer Metastasis Rev 2022; 40:1035-1053. [PMID: 35080763 PMCID: PMC8825433 DOI: 10.1007/s10555-021-10011-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/08/2021] [Indexed: 12/22/2022]
Abstract
Cancer metabolic heterogeneity develops in response to both intrinsic factors (mutations leading to activation of oncogenic pathways) and extrinsic factors (physiological and molecular signals from the extracellular milieu). Here we review causes and consequences of metabolic alterations in cancer cells with focus on hypoxia and acidosis, and with particular attention to carbonic anhydrase IX (CA IX). CA IX is a cancer-associated enzyme induced and activated by hypoxia in a broad range of tumor types, where it participates in pH regulation as well as in molecular mechanisms supporting cancer cells’ invasion and metastasis. CA IX catalyzes reversible conversion of carbon dioxide to bicarbonate ion plus proton and cooperates with a spectrum of molecules transporting ions or metabolites across the plasma membrane. Thereby CA IX contributes to extracellular acidosis as well as to buffering intracellular pH, which is essential for cell survival, metabolic performance, and proliferation of cancer cells. Since CA IX expression pattern reflects gradients of oxygen, pH, and other intratumoral factors, we use it as a paradigm to discuss an impact of antibody quality and research material on investigating metabolic reprogramming of tumor tissue. Based on the validation, we propose the most reliable CA IX-specific antibodies and suggest conditions for faithful immunohistochemical analysis of molecules contributing to heterogeneity in cancer progression.
Collapse
|
37
|
Laughlin TM, Horn JR. Engineering pH-Sensitive Single-Domain Antibodies. Methods Mol Biol 2022; 2446:269-298. [PMID: 35157278 PMCID: PMC9924069 DOI: 10.1007/978-1-0716-2075-5_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There is increasing interest in expanding an antibody beyond high affinity and specificity. One such feature is custom regulation of the binding event, such as pH-dependent control. Here, we provide a methodology for generating single-domain antibodies (sdAbs) that bind their antigen in a pH-dependent fashion. As each sdAb is unique, we start by providing the conceptual framework for designing a combinatorial histidine scanning library within a sdAb-antigen-binding interface. Methods are provided to create a phage display library, containing up to 1 × 1010 unique members where each permutation of histidine substitution is sampled within the confines of the specified interface region(s). Finally, we describe phage display protocols for the selection and analysis of unique pH-dependent sdAb clones.
Collapse
Affiliation(s)
- Tosha M. Laughlin
- Department of Chemistry and Biochemistry, Northern Illinois University
| | - James R. Horn
- Department of Chemistry and Biochemistry, Northern Illinois University,Corresponding author: James R. Horn, Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb IL 60115,
| |
Collapse
|
38
|
Silverstein TP. The Proton in Biochemistry: Impacts on Bioenergetics, Biophysical Chemistry, and Bioorganic Chemistry. Front Mol Biosci 2021; 8:764099. [PMID: 34901158 PMCID: PMC8661011 DOI: 10.3389/fmolb.2021.764099] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
The proton is the smallest atomic particle, and in aqueous solution it is the smallest hydrated ion, having only two waters in its first hydration shell. In this article we survey key aspects of the proton in chemistry and biochemistry, starting with the definitions of pH and pK a and their application inside biological cells. This includes an exploration of pH in nanoscale spaces, distinguishing between bulk and interfacial phases. We survey the Eigen and Zundel models of the structure of the hydrated proton, and how these can be used to explain: a) the behavior of protons at the water-hydrophobic interface, and b) the extraordinarily high mobility of protons in bulk water via Grotthuss hopping, and inside proteins via proton wires. Lastly, we survey key aspects of the effect of proton concentration and proton transfer on biochemical reactions including ligand binding and enzyme catalysis, as well as pH effects on biochemical thermodynamics, including the Chemiosmotic Theory. We find, for example, that the spontaneity of ATP hydrolysis at pH ≥ 7 is not due to any inherent property of ATP (or ADP or phosphate), but rather to the low concentration of H+. Additionally, we show that acidification due to fermentation does not derive from the organic acid waste products, but rather from the proton produced by ATP hydrolysis.
Collapse
Affiliation(s)
- Todd P Silverstein
- Chemistry Department (emeritus), Willamette University, Salem, OR, United States
| |
Collapse
|
39
|
Blaszczak W, Swietach P. What do cellular responses to acidity tell us about cancer? Cancer Metastasis Rev 2021; 40:1159-1176. [PMID: 34850320 PMCID: PMC8825410 DOI: 10.1007/s10555-021-10005-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/22/2021] [Indexed: 12/20/2022]
Abstract
The notion that invasive cancer is a product of somatic evolution is a well-established theory that can be modelled mathematically and demonstrated empirically from therapeutic responses. Somatic evolution is by no means deterministic, and ample opportunities exist to steer its trajectory towards cancer cell extinction. One such strategy is to alter the chemical microenvironment shared between host and cancer cells in a way that no longer favours the latter. Ever since the first description of the Warburg effect, acidosis has been recognised as a key chemical signature of the tumour microenvironment. Recent findings have suggested that responses to acidosis, arising through a process of selection and adaptation, give cancer cells a competitive advantage over the host. A surge of research efforts has attempted to understand the basis of this advantage and seek ways of exploiting it therapeutically. Here, we review key findings and place these in the context of a mathematical framework. Looking ahead, we highlight areas relating to cellular adaptation, selection, and heterogeneity that merit more research efforts in order to close in on the goal of exploiting tumour acidity in future therapies.
Collapse
Affiliation(s)
- Wiktoria Blaszczak
- Department of Physiology, Anatomy & Genetics, Parks Road, Oxford, OX1 3PT, England
| | - Pawel Swietach
- Department of Physiology, Anatomy & Genetics, Parks Road, Oxford, OX1 3PT, England.
| |
Collapse
|
40
|
Proton-gated coincidence detection is a common feature of GPCR signaling. Proc Natl Acad Sci U S A 2021; 118:2100171118. [PMID: 34260394 DOI: 10.1073/pnas.2100171118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The evolutionary expansion of G protein-coupled receptors (GPCRs) has produced a rich diversity of transmembrane sensors for many physical and chemical signals. In humans alone, over 800 GPCRs detect stimuli such as light, hormones, and metabolites to guide cellular decision-making primarily using intracellular G protein signaling networks. This diversity is further enriched by GPCRs that function as molecular sensors capable of discerning multiple inputs to transduce cues encoded in complex, context-dependent signals. Here, we show that many GPCRs are coincidence detectors that couple proton (H+) binding to GPCR signaling. Using a panel of 28 receptors covering 280 individual GPCR-Gα coupling combinations, we show that H+ gating both positively and negatively modulates GPCR signaling. Notably, these observations extend to all modes of GPCR pharmacology including ligand efficacy, potency, and cooperativity. Additionally, we show that GPCR antagonism and constitutive activity are regulated by H+ gating and report the discovery of an acid sensor, the adenosine A2a receptor, which can be activated solely by acidic pH. Together, these findings establish a paradigm for GPCR signaling, biology, and pharmacology applicable to acidified microenvironments such as endosomes, synapses, tumors, and ischemic vasculature.
Collapse
|
41
|
Mills A, Gago F. On the Need to Tell Apart Fraternal Twins eEF1A1 and eEF1A2, and Their Respective Outfits. Int J Mol Sci 2021; 22:6973. [PMID: 34203525 PMCID: PMC8268798 DOI: 10.3390/ijms22136973] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 01/03/2023] Open
Abstract
eEF1A1 and eEF1A2 are paralogous proteins whose presence in most normal eukaryotic cells is mutually exclusive and developmentally regulated. Often described in the scientific literature under the collective name eEF1A, which stands for eukaryotic elongation factor 1A, their best known activity (in a monomeric, GTP-bound conformation) is to bind aminoacyl-tRNAs and deliver them to the A-site of the 80S ribosome. However, both eEF1A1 and eEF1A2 are endowed with multitasking abilities (sometimes performed by homo- and heterodimers) and can be located in different subcellular compartments, from the plasma membrane to the nucleus. Given the high sequence identity of these two sister proteins and the large number of post-translational modifications they can undergo, we are often confronted with the dilemma of discerning which is the particular proteoform that is actually responsible for the ascribed biochemical or cellular effects. We argue in this review that acquiring this knowledge is essential to help clarify, in molecular and structural terms, the mechanistic involvement of these two ancestral and abundant G proteins in a variety of fundamental cellular processes other than translation elongation. Of particular importance for this special issue is the fact that several de novo heterozygous missense mutations in the human EEF1A2 gene are associated with a subset of rare but severe neurological syndromes and cardiomyopathies.
Collapse
Affiliation(s)
| | - Federico Gago
- Department of Biomedical Sciences & “Unidad Asociada IQM-CSIC”, School of Medicine and Health Sciences, University of Alcalá, E-28805 Alcalá de Henares, Spain;
| |
Collapse
|
42
|
Bondar AN. Proton-Binding Motifs of Membrane-Bound Proteins: From Bacteriorhodopsin to Spike Protein S. Front Chem 2021; 9:685761. [PMID: 34136464 PMCID: PMC8203321 DOI: 10.3389/fchem.2021.685761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Membrane-bound proteins that change protonation during function use specific protein groups to bind and transfer protons. Knowledge of the identity of the proton-binding groups is of paramount importance to decipher the reaction mechanism of the protein, and protonation states of prominent are studied extensively using experimental and computational approaches. Analyses of model transporters and receptors from different organisms, and with widely different biological functions, indicate common structure-sequence motifs at internal proton-binding sites. Proton-binding dynamic hydrogen-bond networks that are exposed to the bulk might provide alternative proton-binding sites and proton-binding pathways. In this perspective article I discuss protonation coupling and proton binding at internal and external carboxylate sites of proteins that use proton transfer for function. An inter-helical carboxylate-hydroxyl hydrogen-bond motif is present at functionally important sites of membrane proteins from archaea to the brain. External carboxylate-containing H-bond clusters are observed at putative proton-binding sites of protonation-coupled model proteins, raising the question of similar functionality in spike protein S.
Collapse
Affiliation(s)
- Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics Group, Berlin, Germany
| |
Collapse
|
43
|
Sorge S, Theelke J, Yildirim K, Hertenstein H, McMullen E, Müller S, Altbürger C, Schirmeier S, Lohmann I. ATF4-Induced Warburg Metabolism Drives Over-Proliferation in Drosophila. Cell Rep 2021; 31:107659. [PMID: 32433968 DOI: 10.1016/j.celrep.2020.107659] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 01/30/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022] Open
Abstract
The mitochondrial electron transport chain (ETC) enables essential metabolic reactions; nonetheless, the cellular responses to defects in mitochondria and the modulation of signaling pathway outputs are not understood. We show that Notch signaling and ETC attenuation via knockdown of COX7a induces massive over-proliferation. The tumor-like growth is caused by a transcriptional response through the eIF2α-kinase PERK and ATF4, which activates the expression of metabolic enzymes, nutrient transporters, and mitochondrial chaperones. We find this stress adaptation to be beneficial for progenitor cell fitness, as it renders cells sensitive to proliferation induced by the Notch signaling pathway. Intriguingly, over-proliferation is not caused by transcriptional cooperation of Notch and ATF4, but it is mediated in part by pH changes resulting from the Warburg metabolism induced by ETC attenuation. Our results suggest that ETC function is monitored by the PERK-ATF4 pathway, which can be hijacked by growth-promoting signaling pathways, leading to oncogenic pathway activity.
Collapse
Affiliation(s)
- Sebastian Sorge
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Jonas Theelke
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Kerem Yildirim
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Helen Hertenstein
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Ellen McMullen
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Stephan Müller
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | | | - Stefanie Schirmeier
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
| | - Ingrid Lohmann
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany.
| |
Collapse
|
44
|
Pedersen SF, Flinck M, Pardo LA. The Interplay between Dysregulated Ion Transport and Mitochondrial Architecture as a Dangerous Liaison in Cancer. Int J Mol Sci 2021; 22:ijms22105209. [PMID: 34069047 PMCID: PMC8156689 DOI: 10.3390/ijms22105209] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023] Open
Abstract
Transport of ions and nutrients is a core mitochondrial function, without which there would be no mitochondrial metabolism and ATP production. Both ion homeostasis and mitochondrial phenotype undergo pervasive changes during cancer development, and both play key roles in driving the malignancy. However, the link between these events has been largely ignored. This review comprehensively summarizes and critically discusses the role of the reciprocal relationship between ion transport and mitochondria in crucial cellular functions, including metabolism, signaling, and cell fate decisions. We focus on Ca2+, H+, and K+, which play essential and highly interconnected roles in mitochondrial function and are profoundly dysregulated in cancer. We describe the transport and roles of these ions in normal mitochondria, summarize the changes occurring during cancer development, and discuss how they might impact tumorigenesis.
Collapse
Affiliation(s)
- Stine F. Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark;
- Correspondence: (S.F.P.); (L.A.P.)
| | - Mette Flinck
- Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark;
| | - Luis A. Pardo
- Oncophysiology Group, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
- Correspondence: (S.F.P.); (L.A.P.)
| |
Collapse
|
45
|
Wang Y, Xiang M, Yu Z, Hao Y, Xu Q, Kong S, Wang F, Shi X, Song G, Cao Y, Huang L, Zhu F. A homozygous missense mutation in TBPL2 is associated with oocyte maturation arrest and degeneration. Clin Genet 2021; 100:324-328. [PMID: 33966269 DOI: 10.1111/cge.13993] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/19/2021] [Accepted: 05/04/2021] [Indexed: 11/26/2022]
Abstract
The genetic causes in most of patients with oocyte maturation arrest remain largely unknown. In this study, we identified a homozygous missense mutation (c.895T>C; p.C299R) in TBPL2 (TATA box binding protein like 2) in two infertile sisters with oocyte maturation arrest and degeneration from a consanguineous family by whole-exome sequencing. The TBPL2 mutation is rare and pathogenic, and impaired the transcription initiation function of the protein. Our results showed that TBPL2 mutation might be associated with female infertility due to oocyte maturation arrest and degeneration.
Collapse
Affiliation(s)
- Yu Wang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Mingfei Xiang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Zhaojuan Yu
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Yan Hao
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Qianhua Xu
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Shuai Kong
- School of Life Science, Anhui Medical University, Hefei, China
| | - Fengsong Wang
- School of Life Science, Anhui Medical University, Hefei, China
| | - Xuanming Shi
- Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui, China
| | - Gaojie Song
- Shanghai Key Laboratory of Regulatory, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Yunxia Cao
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| | - Lingli Huang
- Center for Reproductive Medicine, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Fuxi Zhu
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, Anhui, China.,Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, Hefei, Anhui, China
| |
Collapse
|
46
|
Mohanta TK, Mishra AK, Khan A, Hashem A, Abd-Allah EF, Al-Harrasi A. Virtual 2-D map of the fungal proteome. Sci Rep 2021; 11:6676. [PMID: 33758316 PMCID: PMC7988114 DOI: 10.1038/s41598-021-86201-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
The molecular weight and isoelectric point (pI) of the proteins plays important role in the cell. Depending upon the shape, size, and charge, protein provides its functional role in different parts of the cell. Therefore, understanding to the knowledge of their molecular weight and charges is (pI) is very important. Therefore, we conducted a proteome-wide analysis of protein sequences of 689 fungal species (7.15 million protein sequences) and construct a virtual 2-D map of the fungal proteome. The analysis of the constructed map revealed the presence of a bimodal distribution of fungal proteomes. The molecular mass of individual fungal proteins ranged from 0.202 to 2546.166 kDa and the predicted isoelectric point (pI) ranged from 1.85 to 13.759 while average molecular weight of fungal proteome was 50.98 kDa. A non-ribosomal peptide synthase (RFU80400.1) found in Trichoderma arundinaceum was identified as the largest protein in the fungal kingdom. The collective fungal proteome is dominated by the presence of acidic rather than basic pI proteins and Leu is the most abundant amino acid while Cys is the least abundant amino acid. Aspergillus ustus encodes the highest percentage (76.62%) of acidic pI proteins while Nosema ceranae was found to encode the highest percentage (66.15%) of basic pI proteins. Selenocysteine and pyrrolysine amino acids were not found in any of the analysed fungal proteomes. Although the molecular weight and pI of the protein are of enormous important to understand their functional roles, the amino acid compositions of the fungal protein will enable us to understand the synonymous codon usage in the fungal kingdom. The small peptides identified during the study can provide additional biotechnological implication.
Collapse
Affiliation(s)
- Tapan Kumar Mohanta
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa, 616, Oman.
| | - Awdhesh Kumar Mishra
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongsangbuk-do, 38541, Republic of Korea
| | - Adil Khan
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa, 616, Oman
| | - Abeer Hashem
- Botany and Microbiology Department, College of Science, King Saud University, P.O. Box. 2460, Riyadh, 11451, Saudi Arabia
- Mycology and Plant Disease Survey Department, Plant Pathology Research Institute, ARC, Giza, 12511, Egypt
| | - Elsayed Fathi Abd-Allah
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box. 2460, Riyadh, 11451, Saudi Arabia
| | - Ahmed Al-Harrasi
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa, 616, Oman.
| |
Collapse
|
47
|
An acidic residue buried in the dimer interface of isocitrate dehydrogenase 1 (IDH1) helps regulate catalysis and pH sensitivity. Biochem J 2021; 477:2999-3018. [PMID: 32729927 DOI: 10.1042/bcj20200311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/19/2022]
Abstract
Isocitrate dehydrogenase 1 (IDH1) catalyzes the reversible NADP+-dependent conversion of isocitrate to α-ketoglutarate (αKG) to provide critical cytosolic substrates and drive NADPH-dependent reactions like lipid biosynthesis and glutathione regeneration. In biochemical studies, the forward reaction is studied at neutral pH, while the reverse reaction is typically characterized in more acidic buffers. This led us to question whether IDH1 catalysis is pH-regulated, which would have functional implications under conditions that alter cellular pH, like apoptosis, hypoxia, cancer, and neurodegenerative diseases. Here, we show evidence of catalytic regulation of IDH1 by pH, identifying a trend of increasing kcat values for αKG production upon increasing pH in the buffers we tested. To understand the molecular determinants of IDH1 pH sensitivity, we used the pHinder algorithm to identify buried ionizable residues predicted to have shifted pKa values. Such residues can serve as pH sensors, with changes in protonation states leading to conformational changes that regulate catalysis. We identified an acidic residue buried at the IDH1 dimer interface, D273, with a predicted pKa value upshifted into the physiological range. D273 point mutations had decreased catalytic efficiency and, importantly, loss of pH-regulated catalysis. Based on these findings, we conclude that IDH1 activity is regulated, at least in part, by pH. We show this regulation is mediated by at least one buried acidic residue ∼12 Å from the IDH1 active site. By establishing mechanisms of regulation of this well-conserved enzyme, we highlight catalytic features that may be susceptible to pH changes caused by cell stress and disease.
Collapse
|
48
|
He X, Zhu A, Feng J, Wang X. Role of neddylation in neurological development and diseases. Biotechnol Appl Biochem 2021; 69:330-341. [PMID: 33469954 DOI: 10.1002/bab.2112] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/08/2021] [Indexed: 12/13/2022]
Abstract
Neddylation, a posttranslational protein modification, refers to the specific conjugation of NEDD8 to substrates, which is of great significance to various biological processes. Besides members of the cullin protein family, other key proteins can act as a substrate for neddylation modification, which remarkably influences neurodevelopment and neurodegenerative diseases. Normal levels of protein neddylation contribute to nerve growth, synapse strength, neurotransmission, and synaptic plasticity, whereas overactivation of protein neddylation pathways lead to apoptosis, autophagy of neurons, and tumorigenesis. Furthermore, impaired neddylation causes neurodegenerative diseases. These facts suggest that neddylation may be a target for treatment of these diseases. This review focuses on the current understanding of neddylation function in neurodevelopment as well as neurodegenerative diseases. Meanwhile, the recent view that different level of neddylation pathway may contribute to the opposing disease progression, such as neoplasms and Alzheimer's disease, is discussed. The review also discusses neddylation inhibitors, which are currently being tested in clinical trials. However, potential drawbacks of these drugs are noted, which may benefit the development of new pharmaceutical strategies in the treatment of nervous system diseases.
Collapse
Affiliation(s)
- Xin He
- Department of Anesthesiology, Southwest Medical University, Luzhou, Sichuan, People's Republic of China
| | - Ainong Zhu
- School of Clinical Medicine, Southwest Medical University, Luzhou, Sichuan, People's Republic of China
| | - Jianguo Feng
- Department of Anesthesiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China.,Affiliated Xinhui Hospital, Southern Medical University (People's Hospital of Xinhui District), Jiangmen, Guangdong, People's Republic of China
| | - Xiaobin Wang
- Department of Anesthesiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, People's Republic of China
| |
Collapse
|
49
|
Alquezar C, Arya S, Kao AW. Tau Post-translational Modifications: Dynamic Transformers of Tau Function, Degradation, and Aggregation. Front Neurol 2021; 11:595532. [PMID: 33488497 PMCID: PMC7817643 DOI: 10.3389/fneur.2020.595532] [Citation(s) in RCA: 149] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 12/07/2020] [Indexed: 12/11/2022] Open
Abstract
Post-translational modifications (PTMs) on tau have long been recognized as affecting protein function and contributing to neurodegeneration. The explosion of information on potential and observed PTMs on tau provides an opportunity to better understand these modifications in the context of tau homeostasis, which becomes perturbed with aging and disease. Prevailing views regard tau as a protein that undergoes abnormal phosphorylation prior to its accumulation into the toxic aggregates implicated in Alzheimer's disease (AD) and other tauopathies. However, the phosphorylation of tau may, in fact, represent part of the normal but interrupted function and catabolism of the protein. In addition to phosphorylation, tau undergoes another forms of post-translational modification including (but not limited to), acetylation, ubiquitination, glycation, glycosylation, SUMOylation, methylation, oxidation, and nitration. A holistic appreciation of how these PTMs regulate tau during health and are potentially hijacked in disease remains elusive. Recent studies have reinforced the idea that PTMs play a critical role in tau localization, protein-protein interactions, maintenance of levels, and modifying aggregate structure. These studies also provide tantalizing clues into the possibility that neurons actively choose how tau is post-translationally modified, in potentially competitive and combinatorial ways, to achieve broad, cellular programs commensurate with the distinctive environmental conditions found during development, aging, stress, and disease. Here, we review tau PTMs and describe what is currently known about their functional impacts. In addition, we classify these PTMs from the perspectives of protein localization, electrostatics, and stability, which all contribute to normal tau function and homeostasis. Finally, we assess the potential impact of tau PTMs on tau solubility and aggregation. Tau occupies an undoubtedly important position in the biology of neurodegenerative diseases. This review aims to provide an integrated perspective of how post-translational modifications actively, purposefully, and dynamically remodel tau function, clearance, and aggregation. In doing so, we hope to enable a more comprehensive understanding of tau PTMs that will positively impact future studies.
Collapse
Affiliation(s)
| | | | - Aimee W. Kao
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, United States
| |
Collapse
|
50
|
Park KC, Krywawych S, Richard E, Desviat LR, Swietach P. Cardiac Complications of Propionic and Other Inherited Organic Acidemias. Front Cardiovasc Med 2020; 7:617451. [PMID: 33415129 PMCID: PMC7782273 DOI: 10.3389/fcvm.2020.617451] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022] Open
Abstract
Clinical observations and experimental studies have determined that systemic acid-base disturbances can profoundly affect the heart. A wealth of information is available on the effects of altered pH on cardiac function but, by comparison, much less is known about the actions of the organic anions that accumulate alongside H+ ions in acidosis. In the blood and other body fluids, these organic chemical species can collectively reach concentrations of several millimolar in severe metabolic acidoses, as in the case of inherited organic acidemias, and exert powerful biological actions on the heart that are not intuitive to predict. Indeed, cardiac pathologies, such as cardiomyopathy and arrhythmia, are frequently reported in organic acidemia patients, but the underlying pathophysiological mechanisms are not well established. Research efforts in the area of organic anion physiology have increased dramatically in recent years, particularly for propionate, which accumulates in propionic acidemia, one of the commonest organic acidemias characterized by a high incidence of cardiac disease. This Review provides a comprehensive historical overview of all known organic acidemias that feature cardiac complications and a state-of-the-art overview of the cardiac sequelae observed in propionic acidemia. The article identifies the most promising candidates for molecular mechanisms that become aberrantly engaged by propionate anions (and its metabolites), and discusses how these may result in cardiac derangements in propionic acidemia. Key clinical and experimental findings are considered in the context of potential therapies in the near future.
Collapse
Affiliation(s)
- Kyung Chan Park
- Department of Anatomy, Physiology and Genetics, Burdon Sanderson Cardiac Science Centre, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Steve Krywawych
- Department of Chemical Pathology, Great Ormond Street Hospital, London, United Kingdom
| | - Eva Richard
- Centro de Biología Molecular Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Cientificas (UAM-CSIC), Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), IdiPaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lourdes R Desviat
- Centro de Biología Molecular Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Cientificas (UAM-CSIC), Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), IdiPaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Pawel Swietach
- Department of Anatomy, Physiology and Genetics, Burdon Sanderson Cardiac Science Centre, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| |
Collapse
|